1. Field of the Invention
The present invention relates to a ventilating fan, particularly to a fire damper for a ventilating fan.
2. Description of the Related Art
A ventilating fan is a common air exchanging equipment. As shown in FIGS. 1A and 1B, a conventional ventilating fan 100 is provided. The ventilating fan 100 comprises a frame 110 having an opening, a fan 111 and electrical components 112 for driving the fan provided in the frame 110, an adapter 113 provided at air outlet of the fan 111 and connected to pipes to the outdoor, and, a mask 101 provided at an opening section of a ceiling 116 and communicated to the frame 110.
In accordance with the provisions of the laws and regulations in various countries, a refractory protection should be mounted at an air inlet of the ventilating fan to mostly completely isolate the air inlet of the ventilating fan from the indoor. That is, once a fire breaks out, intercommunication (air circulation) between the outdoor and the indoor will be cut off by the refractory protection.
Accordingly, a fire damper 200, as the refractory protection, between the frame 110 and the mask 101 of the ventilating fan 1 having above-mentioned configuration, is needed.
The fire damper 200 comprises a frame 230 having a flange 220 of a quarter shape provided therein and a shutter 210. The shutter 210 comprises a shutter curtain 211, springs 212 provided at both sides of the shutter curtain 211, mounting clamps 214 for the shutter curtain 211, made of thermal fuse components 213, for example tin alloy, etc. The shutter curtain 211 of the shutter 210 is mounted over the flange 220 (that is, near the frame 110 of the ventilating fan) in a folded state. The fire damper 200 is fixed on the frame 110 of the ventilating fan. The mask 101 is mounted on the fire damper 200.
Meanwhile, once an emergency, such as a fire, happens, the thermal fuse components 213 will burn out and the springs 212 will spring out to close up the shutter, so that intercommunication to the outdoor will be cut off around the flange 220. However, once an illumination device 102 is mounted on the mask of the ventilating fan 100, a power cord 103 for the illumination device 102 usually passes through the opening section of the ventilating fan 100 and then is connected to electrical components 112 for the ventilating fan 100. In this case, if a fire damper 200 is provided between the mask 101 and the ventilating fan 100, the power cord should be arranged to keep away from the shutter 210 so as to avoid interference between the shutter 210 and the power cord during closing of the shutter 210.
Like the mask of an illuminating device, for the masks through which the power cord is connected to the ventilation fan and the masks through which no power cord will pass, they cannot share the same fire damper. In the meanwhile the cost of the ventilating fan is reduced.